Density factor approach to representing impact of die power maps on thermal management

In the microelectronics industry, power has traditionally been the key driver for thermal management. Cooling solutions are typically rated in terms of their power dissipation capacity and efficiency. However, overall power is not the only parameter that affects thermal management. For instance, it is well-known that power density is also important (i.e., it is easier to cool 50 W uniformly distributed on a 20×20 mm die than the same power on a 10×10 mm die). Furthermore, even if the die size remains unchanged, nonuniform power distribution at the die level can create localized regions of high power density that require thermal management. This paper proposes a simple metric, density factor (DF_jx), to be used in conjunction with power for quantifying the impact of power density on a given thermal solution. The advantages, limitations, and applicability of this metric are discussed.